Method of and apparatus for applying coating



L. H. PARKER AND H. W. DAY..

METHOD 0F AND APPARATUS FOR APPLYING COATING.

APPLlcATloN man Uc.

2 SHEETS-SHEET l.

Patented Ang. 8, 1922.

laufen/$021.5: Leel Paaucea",

APPLICATION FILED 0C? 9,1920.

Patented Aug. 8, 1922.

2 SHEETS-SHEET 2 UNITED s'm'ljlasm LEE H. PARKER,

eAfrEN'r OFFICE.

OF BOSTON, AND HERBERT W. DAY, OF WOLLASTON, MASSACHU- SETTE, ASSIGNORS T0 SPRAY ENGINEERING COMPANY, OF BOSTON, MASSACHU- B ETTS, A CORPORATION 0F MASSACHUSETTS.

METHOD OF AND APPARATUS FOR APPLYING COATING.

Specification of Letters Patent.

Patented Aug. 8, 1922.

Application Med October 9, 1820. Serial No. 415,737.

To al? whom, 'it ymay concern:

Be it known that we. LEE H. PARKER and HERBERT iV. DAY, citizens of the United States, and residents, respectively, of Boston and Wollaston. in the counties, respectively, of Suffolk and Norfolk, State of Massachusetts. have invented an Improvement in Methods of and Apparatus for Applying Coating` of which the followingr description, in connection with the accompanying drawings, is a specification, like characters on the drawings representing like parts.

This invention relates to the method of and apparatus for applying coating and which while it may be of general application and applicable to coating applying devices, apparatus and methods of various types, is in the disclosed embodiment an improvement upon the invention disclosed in the patent to Herbert lV. Day. No. 1,321.014, dated November 4, 1919.

The coating, if a liquid, may be a paint, japan, varnish or other suitable coating medium. or it may if desired be a solid in powdered form, and the material or surface to which it is to be applied may be of any character such for-*example as wood. metal or other material.

An important object of our invention is to provide an industrial tool or appliance and to perfect a methodivhereby paint or other coating material may be projected onto a surface, and even at some considerable distance from the user of the tool or appliance, without any scattering of the coating material beyond those parts of the surface that are intended to be coated. Other objects of the invention will be set forth hereinafter.

Referring more particularly to the drawings wherein we have represented certain embodiments of our invention and disclosed the best means known to us for practising our method,- p

Fig. 1 is a vertical longitudinal section of a tool constructed in accordance with our invention;

Fig. Q is a plan view of the discharge end of the tool constructed in accordance with our invention;

Fig. 3 is a side elevation of the discharge end of a coating tool disclosing a slightly modified form or embodiment of the mechanism of our invention;

Fig. 4 is a plan view of one of the deflectors for a supplemental air jet:

Fig. 5 is a dia rammatic representation indicating the disc arge from the tool of the coating material, the main air )et and the deiected supplemental air jets, and the conse uent or resulting action;

ig. 6 is a diagrammatic representation corresponding to a transverse section upon the line 6--6 of Fig. 5; and

Fig. 7 is a similar representation corresponding to a transverse section upon the line 7-7 of Fig. 5.

We shall proceed to describe our invention as applied to a paint gun or coating appliance like that sho-wn in the said patent to Day, but it is distinctly to be understood that our invention is in no wise limited in its application to such type of gun or appliance, but that it may be employed upon guns or appliances of various other types. The ensuing description therefore of one type of gun or appliance to which the invention is applied is in no sense a. limitation upon the scope of our invention.

The tool or appliance may be of any suitable material but is preferably metallic and may be of the general form shown in the patent to Day, No. 1,172,233, dated February 15, 1916, or of any other suitable form or construction. The body 1 is preferably provided with a handle or extension 2 integral therewith and provided with a guard 3 enclosing the free end of the valve operating lever 4 pivoted at 5 upon the body 1. The said operating lever 4 is represented as of general trigger' form.

The handle 2 is rovided with a passage 6 for the paintl or other suitable coating liquid or powder which may be supplied through gravity or under preure if desired and also with a passage. 7 for the air or other suitable fiuid under pressure. In the form of tool herein shown we have represented the passages 6, T, as pipes suitably secured in the body 1 and as communicating at their inner ends with passages 8, 9 cored or otherwise suitably provided in the body 1. Controlling the paint supply passage 8 is a valve which may be of any suitable form, but which is herein represented as an axially movable piston or plunger 10 positioned within a valve casing 11 and having a stem 1Q extending through the valve casing into contact With the operating lever 4, as clearly shown in Fig. 1. The valve here shown as a piston or plunger is normally held seated hv a coiled s ring 13 surrounding the stem 12 and seat in a recess 14 in a cap 15 threaded at 16 into the body 1 which is similarly threaded at 17.

The passage 9 for the air is controlled b a similar valve not herein shown, but pre erably the same as the correspondinlgI valve 18 shown in Fig. 2 of the patent to erbert lV. Dav, 1921, the spindle of such valve contacting with the valve operating lever preferably so shaped as to engage both valves.

The body 1 1s cored to rovide a lon tudinal passage 20 whic is interna y threaded at 21, 22 for the reception res ectively of a. tubular member 23 `threade at 24 and a needle valve 25 threaded at 26. The tubular member 23 at its forward end is preferabl suitably formed to permit the passage of tlie coating material issuing from the valve chamber 1() into the passage 27 and thence into the circumferential space 28. For this purpose the forward end of the tubular member is preferably square at 29. Thus the coating material when the valve 10 is opened is permitted to flow through the passage 6, the valve casing 11, the passages 27, 28, and thence past the uare formation 29. Upon the forward end o the tubular member 20 is threaded or otherwise positioned a ca 30, which may if desired be similar to t e corresponding member in the said Day Patent No. 1,172,233. The needle valve 25 is seated at the outer end in the cap 30 as indicated in Fig. 1, and the forward end of the said needle valve is guided and positioned by any suitable means, as for example by a coiled wire 31 encircling the head of the valve and maintaining it in a central position when the valve is unseated. The rear end of the valve 25 may be provided with a suitable lock nut 32.

The air passage 9 is in communication with a passa e 33 indicated in dotted lines in Fig. 1, an which is itself in communication with the valve chamber containin the valve 18. Extending from such valve c amber is an air passa e 34 indicated in dotted lines in Fig. 1 an communicating with a passage 35 for'min an enlargement of a passage 36 of the tu ular member 20. When the valve casing is opened. the air flows through the passage 33, past the valve 19, through the passages 34, 35, and into the passage 36 ,governed or controlled by the needle valve 25.

Upon the outer end of the body 1 is threaded or otherwise suitably secured a preferably cap-like member 37 herein shown as having a concaved or curved inner surface 38 and a small central opening 39 in line with the axis of the needle valve 25. The length of the threaded portion 40 of the cap like member 37 is sufficient to permit adjustment of the member 37, so as to pro- No. 1,368,612, dated February 15,V

vide for the effective formation of a film and the variation of the thickness thereof as described in the said Day Patent No. 1,172,233. Such film is constantly formed and maintained by capillary action between the surface 38 and the outer surface 41 of the inner cap 30, which are brought close enough together to insure such action., The air entering through the passage 36 breaks through the film at the central part of the cap `and discharges the same upon the work in very fine lobules. Said film is constantly broken by t e air or other Huid, but is constantly restored through the action of capillarity. Hence the coating material may be merely under suction due to capillary action. The maintenance of the supply of coating material is not dependent upon the presence of the air pressure which is used merely to break the film and discharge the globules. We effect through the described construction a very fine division of the coating material as set forth in the said Day Patent No. 1,172,233.

While We have described at some len th means whereby a film of coating materia is formed, disrupted and discharged, we desire it to be understood that our invention is not limited in its application to the formation of a film, since the coating material may be brou ht or supplied to the point of ultimate disc arge in any suitable manner, whether as a film formation or otherwise, or as shown for Burdick, No. 649,430, dated May 15, 1900, and in the patent to De Vilbiss and Mueller, No. 1,260,522, datedV March 26, 1918.

The construction of parts thus far described effects the formation of a mass of spray of general conical form issuing through the orifice 39, but generally circular in cross section, and substantially as indicated at a in Fig. 6. This result is effected by the disrupting of the film formed between the caplike members 30, 37, through the agency of the air or other suitable fluid in the manner already described.

As disclosed in the said Day Patent, No. 1 321,014, means have heretofore been provlded for discharging supplemental jets of air upon the discharged spray for the purpose of changing the shape of the discharged spray from circular form into that of a relatively thin sheet, the disclosure in the said Day Patent No. 1,321,014 being of means whereby the mass of spray as discharged is given any form between that of a relatively thin sheet and a cone or mass circular in cross section.

IOur invention constitutes an advance and an improvement upon those tools or appliances having means for discharging supplemental jets of air upon the discharged coating material, and as previously stated is not limited in its application to those example in the patent to` 'break up the coatirg types of tools or appliances wherein a film formation is created or established. We will, however, disclose the essential features of our invention as ap lied to a tool or appliince wherein such (ilm formation is create In the use of the tool of our invention we are enabled to break up the coating materialinto globules or articles of any desired iineness. The paint or other coating material is broken up by the air issuing past the needle valve 25 to a certain degree of fineness, but it is frequently desirable to material to greater degrees of fineness. providing supplemental air jets under fu l force or pressure, the coating material is broken into particles or globules of the most extreme ineness. By modulating or varying the pressure of the supplemental air jets any desired intermediate degree of iineness of the coating particles is secured.

In the disclosed embodiment of the invention, we provide a generally cylindrical conical member 42 having any suitable number, and herein two, tubular extensions or passages 43, 44, preferably diametrically opposed to each other and terminating in discharge passa es 45, 46 parallel as shown or slightly inclined toward each other, and; clearly represented in Fig. 1. We may employ fewer or more than two supplemental discharge passages.

The two supplemental air passages 43, 44 and 45, 46 are respectively in constant communication at their inner ends through passages 47, 48 with an annular passage or groove 49 shown as formed in the outer surface of the forward end of the body 1 and communicating through the longitudinally extending passage 49 with a passage 50 in the body member 1 and which is in communication with the main air passage 35 through a small port 51. This port is controlled by a valve 52 threaded into an opening 53 of the body 1 and having a preferably knurled head 54 by which it may be turned manually. The inner tapered head 55 of said valve is adapted to be seated so as to close the port 51 or to be opened fully or to any desired extent, thus regulating the air supply through the said passage 50. The valve 52 constitutes a reducing valve whereby the supplemental air pressure can be regulated if desired and whereby any desired degree of ineness of the discharged coating material may be obtained. Obviously the annular groove 49 may be formed in the inner surface of the member 42.

In order effectively to seat and control the position of the cylindrical member 42, the body 1 is herein shown as provided with a spherical surface 56 upon which is received the correspondingly shaped inner surface 57 of the cylindrical member 42. Co-

operating with the said spherical seat is the guiding surface 58 of the cap-like member 37.

With said guiding surface 58 there contact the projections 59, 60, which extend from the walls of the supplemental air supply passages 43, 44. This construction may be varied as desired.

Cooperating to hold the cylindrical member 42 in position, there is desirably provided a coiled spring 61 between the inner end of the cap-like member 37 and the cylindrical member 42.

While in the disclosed embodiment of the invention the supplemental air passages 47, 48 are represented as in constant communication with the annular groove or passage 49, whatever be the circumferential position of the cylindrical member 42, our invention obviously is not limited to such feature of constant communication, although this is desirable. In other types of tools or appliances to which our invention may be applied, the supplemental air passage or passages may not be in constant communication with the source of compressed air supp However, in the disclosed type or embodiment of our invention the discharge of the supplemental air jets is not interrupted or cut off by movement of the cylindrical member 42, but through the manipulation of the valve 62. Our invention, however, is not limited in this respect.

In the said Day Patent 1,321,014 the supplemental jets of air are discharged through orifices which are inwardly directed or inclined toward the axis of the tool or appliance, or rather toward an outward prolongation of the said axis. In such other types of coating tools as we are familiar with, the supplemental air jets are discharged at an inward inclination so as to intersect, if but very little extended. a prolongation of the axis of the tool. The general result of such construction is to transform the discharged coating material from a mass circular in cross section into the form of a relatively thin sheet, though as already stated, in the case of said Day Patent 1,321,014 any form between that of a circle and a relatively thin sheet may be secured.

In all said cases, however, the supplemental air jets are discharged directly onto the discharged coating material at a point close to the point of ultimate discharge of the coating material from the tool. In none of said cases has any attempt been made to create by the supplemental air jets protective sheathings or air walls that substantially encompass or partially surround the discharged coating material which has been reduced to a sheet like condition.

In accordance with the broad scope and purpose of our invention we provide for e discharge of the supplemental air jet or jets in such a way and with such a result that the said fjets themselves become or are more or less attened out or transformed into layers of air as diagrammatically indicated at A B Fig. 7, and which position themselves at the opposite faces of the discharged coating material. Thus the supplemental air ets perform several important results.

hey serve first to flatten the discharge or spray of coating material into a general sheet like form and since they themselves are more or less flattened in accordance with our invention, they secondly constitute a protecting sheathing or envelope or an air wall or walls which effectively prevent the outlying or smaller particles of the coating material from disseminating or flying onto any part of the surface that is not desired to be coated. On the contrar all the outlying particles are guided an directed in such a way that all the discharged coating material is received u on the surface in a relatively thin line. T e result is that the user ofthe tool or appliance or the practicer of our method may stand at a considerable distance from a wall or other surface that is to be coated and may project the coating material in the described relatively thin line upon the exact parts of the surface desired without overlapping onto adjacent parts of the surface or onto other surfaces. i

The method of our invention may be carried out or practised in various ways and the means of our invention may be embodied in various types or yforms of tools.

Preferably, however, we carry out our invention in substantially the following manner.

Referring to Figs. l, 2 and 5, we have represented each of the two tubular extensions 43, 44 as having deflecting prolongations 62, 63 here shown as integral with said extension 43, 44, though obviously they may be attached thereto either ermanently or removably. Preferably t e discharge passages 45, 46 are in parallelism with the axis 'of the tool and they may be of any suitable shape in cross section, being for example elongated more or less in cross section. The air issuing through said passages `45, 46 strikes the prolongations 62, 63 and when the same are'positioned as shown in Fig. 1, the air strikes them at their inner faces. We have here represented each of said prolongations as having a somewhat abruptly inclined part 64, 64 merging into a less abruptly inclined portion 65, 65a. The air discharged through the supplemental jet passages 45, 46 is guided or deflected by the surfaces 64, 64, 65, 65, in two sheets A, B, as diagrammatically indicated in Fig. 5 and which when the said prolongations 62, 63, are inclined as shown, gradually approach each other and would ultimately meet at substantially the point C which may be several feet in advance of the discharge end of the tool on appliance. If, however, the prolonations 62, 63 are at their inner faces paralel with each other, or substantially parallel, then the two sheets of air A, B, will continue in substantially parallel paths, but still constitute air walls or a sheathing or protective layers at opposite sides of the coating material. In the lattercase, however, the coating material will not be reduced to a thin layer or be receivedin as thin a line upon the surface to be coated as would be the case where the said prolongations are inclined toward each other substantially as indicated in Figs. 1 and 5'.

The said prolongations 62, 63 are desirably of increasing lateral extent as is clearly evident from an inspection of Fig. 2. This feature cooperates in the transformation of the supplemental air jets into air sheets or layers. Viewing Fig. 5, it will be evident that the coating material as discharged from the tool or appliance is at first of a general conical form as indicated by the lines E, F in said figure. At some such point as indicated by the section line for Fig. 6, the spreading discharged coating material is encountered by the two sheets of air, A, B, from the supplemental discharge passages and under the influence of the said sheets o air which are traveling in the general direction A, B, the said discharged mass of coating material'is gradually reduced in form to a relatively thin sheet at some point between the section line 6-6 and the point C. Thus not only is the coating material reduced to a relatively thin sheet and is deposited in a relatively thin line, but the coating material is substantiall sheathed from the instant of its discharge rom the tool to the instant of its reception by the surface to be coated.

We have stated that the prolon ations may be secured to the tool instead o being integrally formed at some part thereof. In 110 Fig. 3, we have represented prolongations 66, 67, the inner ends 68 whereof are received in slots or openings in small lateral projections 69 formed upon the tubular extensions 43, 44. Set screws 7() or other suitable means 1.15 are provided to secure the said prolongations in position, but detachably so as to permit them to be removed to be replaced by others of other size or form, or in case it is desired not to use them, as in classes of work 120 not calling for the creation of a relatively thin sheet of coating material.

The said prolongations may in any case be of various forms, and in Fig. 4, we have representedone of the prolongations as sub- 12b stantially elliptical in outline.

In describing our invention, we have referred to the discharge of opposite supplemental air jets, but it is obvious that our invention is not thus limited in its application. 130

In certain cases we may wish to employ more than two prolongations or deflectin means, as, for example, four, where a di ferent form or sha e of the mass of coating material at the polnt of final application to the surface to be coated is desired. In such case, the prolongations need not at their inner surfaces be inclined toward each other, but may be parallel with each other, or might be even Slightly divergent. Moreover in certain classes of work, we may rovide but a single prolongation at one si e of the ma of discharged coating material, as, for example, where it is desired to provide a protective air coating or layer along certaln parts only of the work.

We have described the prolongations, abutments, or parts as so located that the supplemental air discharge impinges upon the inner surfaces of said prolongations. Our invention, however, is not limited in this respect, since within the broad purpose and scope of our invention, the said prolongations may be positioned at any suitable point and may receive the impact of the supplemental air jets thereon in any suitable manner, provided the result is to cause said supplemental air jet or jets to act as protective air wall or walls, envelopes or layers for the discharged coating material.

We may efl'ect the formation of the protective layer, sheathing or envelope, and particularly the formation of a relatively thin sheet of the coating material, in any suitable way.

Having thus described one illustrative ernbodiment of our invention and the best mode known to us for carrying out our process, we desire it to be understood that although specific terms are employed they are used in a generic and descriptive sense and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Claims:

1. Means for a plying coating comprising means to supp y coating material, means to subject the same to the action of compressed air, thereby effecting the discharge of the coating material, means to discharge compressed air supplementally upon the discharged coating material at opposite sides of the discharge of coating material, thereby reducing said discharge of coating material to sheetV form flaring rom the point of discharge therefrom and unconfined at its edges, and means whereby the sup lementally discharged air is itself reduced to sheet form flaring from its points of discharge and unconfined from the edges thereof, so as to constitute substantially coincidently flaring, air-Wall sheets for the said flaring sheet o discharged coating material.

2. Means for applying coating comprising means to supply coating material, means to subject the same to the action of a motive agent, thereby effecting the discharge of the coating material, means to discharge the mo tive agent supplementally upon` the discharged coating material at opposite sides of the ischarge of coating material, thereby reducing said discharge of coating material to sheet form flaring from the point of discharge therefrom and unconfined at its ed es, and means whereby the motive agent is itself reduced to sheet form flarin from its points of discharge and unconfine from the edges thereof, so as to constitute substantially coincidently flaring, protective, airwall sheets for the said flaring sheet of discharged coating material.

3. That method of applying coating comprising supplying coating material, discharging a motive agent against said coating material, thereby effecting the discharge of Said coating material as a mass or cloud, supplementally discharging a motive agent upon the discharged coating material at opposite sides of the discharge of said coating material, thereby reducing said discharge of coating material to sheet form flaring from the point of discharge thereof and unconfined at its edges, and reducing to sheet form flaring from its points of discharge the supplementally discharged motive agent without confining said supplemental discharge at the edges thereof, whereby substantially coincidently flaring, protective, air-wa1l sheets are constituted for the flaring sheet of discharged coating material.

4. That method of applying coating comprising supplying coating material, discharging compressed air against said coating material, thereby effecting the discharge of said coatin material as a mass or cloud, supplementa ly discharging compressed air upon the discharged coating material at opposite sides of the discharge of said coating material, thereby reducing said discharge of coating material to sheet form flaring from the oint of discharge thereof and unconfine at its edges, and reducing to sheet form flaring from its points of discharge the supplementally discharged compressed air without confining said supplemental dischar e at the edges thereof, whereby substantial??7 coincidently flaring, rotective, air-wal sheets are constituted or the flaring sheet of discharged coating material.

5. Means for applying coating comprising means to supply coating material, means to subject the same to the action of compressed air, thereby effecting the discharge of the coating material, means to discharge cornpressed air supplementally upon the discharged coating material at opposite sides f of the discharge of coating material, thereby reducing said discharge of coating material to sheet form Haring from the point of discharge therefrom and unconned at its edges,

members having a general paralle and means including members extending in the general direction of" discharge and also toward each other, whereby the supplementally discharged air is itself reduced to sheet form flarin from its points of discharge and uncon ned at its edges, so as to constitute coincidently flaring, protective, air-wall sheets for the flaring sheet of dischar d coating material.

6. leans for applying coating comprising means to supply coating material, means to subject the same to the action of compressed air, thereby effecting the discharge of the coatin material, means to discharge compresse air supplementally upon the discharged coating material at opposite sides of the discharge of coating material, thereby reducing said discharge of coating material to sheet form flaring from the point of discharge therefrom and unconfined at its edges, and means including two opposed, plate like relation but slightly inclined toward each other, Whereb the supplementally discharged air is itsel reduced to sheet form llarin from its points of discharge and unconline at its edges so as to constitute coincidently flaring, protective, air-wall sheets for the flaring sheet of discharged coating material.

7. A paint gun or tool comprising a bod having means to supply coating materia, means to subject the same to the action of compressed air, thereby to effect the discharge of the coating material, means to discharge compressed air supplementally upon the discharged coating material at opposite sides of the discharge of coating material, thereby reducing said discharge of coating material to sheet form flaring from the point of discharge thereof and unconlined at its edges, and plate like members 62, 63 carried by the gun or tool and extendin in the eneral direction of discharge to re uce to s eet form with unconined lateral edges the supplemental air discharge.

8. Means for applying coating comprising means to supply coating material; means to subject the same to the action of a motive agent, thereby effecting the discharge of the coating material, means including a plurality of small orifices respectively to dischar e the motive agent supplementally upon t e discharged coating material at opposite sides of the discharge of coating material, thereby reducing said discharge of coatin material to sheet form flaring from the point of discharge` therefrom, and means of markedly greater width than the diameter of `said orifices, to reduce the said supplementally discharged motive agent to sheet form flaring markedly from said orifices, so as to constitute substantially coincidently flaring, protective, air-wall sheets for the said flaring sheet of discharged coating material.

In testimony whereof, We have signed our names to this specification.

LEE H. PARKER. HERBERT W. DAY.

eoV 

